1. Field of the Invention
The present invention relates to flame retardant, impact-modified polycarbonate/polylactic acid compositions which contain a salt of a phosphinic acid and exhibit improved heat resistance, toughness and flame resistance, and to the use of the flame retardant, impact-modified polycarbonate/polylactic acid compositions for the production of mouldings and the mouldings themselves.
2. Description of Related Art
WO-A 2006/030951 A1 discloses compositions containing 95-5 wt. % polylactic acid (PLA) and 5-95 wt. % aromatic polycarbonate, based in each case on the sum of the two components, an acrylic resin or a styrene-grafted acrylic resin, another polymer grafted or copolymerised with a glycidyl component and at least one compatibilising agent from the group of the oxazolines, oxazines and carbodiimides.
DE-A 10 2007 061 760 discloses impact-modified polyalkylene terephthalate/polycarbonate compositions which contain a salt of a phosphinic acid, the use of the impact-modified polyalkylene terephthalate/polycarbonate compositions for the production of mouldings and the mouldings themselves.
While plastics are increasingly replacing metals and wood in many areas of technology and everyday life, and work is being carried out intensively on improving their properties and opening up new areas of application, however, a large proportion of these plastics are based on non-renewable raw materials such as petroleum, stocks of which are limited.
In the past few years, therefore, on the one hand processes for the recycling of plastics and on the other hand plastics based on renewable raw materials, e.g. polylactic acid (PLA), have been developed. One problem with this, however, is that often these plastics do not yet achieve the specifications and properties of the established materials.
Thus, for example, it is known that with PC/PLA (polycarbonate/polylactic acid) blends, improved flame resistance can be achieved by adding phosphate-containing flame retardants. However, these flame retardant blends generally display low heat resistance and reduced toughness, which is inadequate for the desired areas of application.